Folded dipole antenna



Oct, 2, 1951 E. c. HAMEL. ET AL FOLDED DIPOLE ANTENNA Filed April 2,1949 and,

Patented Oct. 2, 1951 UNITED STATES PATENT OFFICE FOLDED DIPOLE-ANTENNAEdward C. Hamel, Itasca, Glenn A. Brown, Lombard, and Robert F. Pond;Chicago, Ill., assignors to Teleflex Antenna 00., Chicago, Ill., acorporation of Illinois Application April 2, 1949, Serial No. 85,226

k Claims. 1

The present invention relates to an antenna for thereception ortransmission of radio waves, and more particularly to an antennaespecially adapted for the reception of television andfrequencylmodulated signals.

D'ueto thedifii'culty. in obtaining asatisfactory signal for televisionor frequency modulated radio receivers without resorting-to elaborateand expensive outdoor antennae, and also because in many-areas suchoutdoor antennae are not permittedby reason of'various restrictions,many Homes and apartments are without such receivers.

Eurthermorasuch outdoor antennae have been quite-expensive to installand as they require care na of'a' more uniformamplituderesponse overa'widerange of frequencies thanlpossible with prior commercial :types ofindoor (antenna, and

which response compares very favorably with the expensive and elaborateoutdoor antennae now employed;

Another'important object of the present invention is the provisionof'a'novel folded 'di -pole antenn'a" havingjan' impedance closelyapproximating the "input impedance of standard television receivers.-The novel ant'enna'of the present inventionisso designed and"constructed as to pro viderbroadfrequency response, a condition highlydesirable forrtheproper reception of television signalsand'notpossessedby any prior type of indoor "or-portable antennae.

The present invention further comprehends the provision of anovel'ante'nnathatmay be dis-. posed closely adjacent thereceiver,requiring, a

minimumiofspace, and one that is quickly and], easily? adjusted for".most. effective reception.

Wherrnotin'use', theinovel antenna forms a com pactass'embly that" maybecollapsed into a small space'and 'mounted on the receiver or manyinconspicuous plaoe, butian antenna is instantly available forreception-when the, receiver is to be" operated; By reason ofr'the novel"constructiomk 2 combination and arrangement embodied inthe presentantenna, reception of'the standard television receiver is greatlyenhanced, a condition not found in prior types of antennae available forindoor use.

The invention furthencomprehen'ds the provision of a novel di-poleantenna comprising. a pair of connected spring-loaded, concave tapesformed ofa substantiallyrigid conducting metal,

and which tapes may be readily adjusted to a de-" sired length foroptimum reception of television signals in a prescribed or availablechannel.

In the preferred embodiment, the novel antenna comprises a paifof coilsof conducting material, each coilbeing inthe form of 'a con; caved andsemi-rigid, tempered steel tape mount ed in a non-conductinghousing in*such manner that the steel tapes may be uncoiled and with drawn anydesignated amount for the effective;

reception of signals in'a prescribed or designated channel, and whensowithdrawn forming a folded di-pole antenna. These tapes when foldedinf the manner intended, are self-supporting at whatever length iswithdrawn from the house ing;

Further objects'are'to provide a construction" of maximum simplicity,efficiency, economy and ease of assembly and operation, and such furthernbjects, advantages and capabilities as will later more fullyappearand are inherently pos-' sessed thereby.

The invention further resides'in the construe tion, combination andarrangement of parts illustrated in the accompanying drawing, and whilethere is shown therein a preferred embodiment;

it is to be understood that the same is susceptible j of modificationand change, and comprehends other details, arrangements of parts,features and constructions without departing from the spirit of theinvention;

In the drawing: a

Figure liis a'view in perspective of thenovel antenna. assembly with thetapes retracted to in operative position.

Fig. 2 is another view in perspective of the novel antenna assembly butwiththe tapes with drawn to form two angularly arranged andselfsupported antenna elements.

Fig. 3'is anenlarged view in rear elevation of the novel assembly withthe rearpanel removed to disclose the interior, one of the antennaelements being shown in retracted position'and the other partiallywithdrawn, and the casing for one of "the elements or tapes being brokenaway to show the tape coiled within the casing.

Fig. 4 is a cross-sectional view takenon the irregular line i of Fig. 3,but omitting the tapes and casings. v

Fig. 5 is a view in vertical cross section taken on the irregular line5--5 of Fig. 3.

Fig. 6 is a fragmentary view in perspective of the inner end of anantenna element or tape.

Fig. 7 is a fragmentary enlarged view in rear elevation of an alternateconstruction of housin for receiving the tapes.

Referring more particularly to the drawing and to the illustrativeembodiment shown in Figs. 1 to 5, inclusive, there is disclosed ahousing I formed or molded of a non-conducting material such as asuitable plastic composition having sufficient rigidity, inherentstrength and insulating characteristics as to provide a casing for thereception and mounting therein of theantenna.

tected but to which access may be quickly had;

byremoval of a screw or securing means 3 adaptto be received in athreaded boss 4 disposed on the interior of the housing.

The interior of the housing is further provided with opposed arcuateflanges or ledges 5 and 6 each so contoured as to receive and support infixed position a metallic casing 1 containing an antenna member orelement 8. Each antenna member or element 8 comprises a spring-loaded,semi-rigid and concaved conducting tape preferably formed of temperedsteel which may be coated or plated with a conducting surface covering.

The outer end 9 of each tape is withdrawn through an opening I in thecasing I, and the portion between this end and the portion coiled withinthe casing is bent back to form a folded di-pole with the antennamembers projecting outwardly and upwardly in angular relation and thesections 8 and 8 of the tape disposed in spaced relation. The opposedends 9 of the two antenna members are joined together by a flexibleconnection It]. The tape 8 within each casing l is electricallyconnected to its casing by its sliding contact therewith where the tapeemerges, and each casing 1 in turn is electrically joined at H to aconductor or cable A connecting the antenna to thereby transmit theenergy intercepted by the antenna to the receiver.

To prevent the outer ends 9 from being withdrawn from the housing I, theextreme ends thereof are formed with a lateral projection l2 thatprevents withdrawal of the end of the tape from between a pair ofclosely spaced, parallel flanges or ribs I 3 and I4 formed upon orcarried by an arm 15 freely pivoted at I6 at its inner 7 reduced end.These flanges or ribs are of substantial length and spaced apart justsufficient to receive therebetween the folded, convex, outer end 9 ofeach tape or antenna and with the adjacent portion of the tape extendingoutwardly through an elongated notch or slot I! in the opposite side orend walls l8, I8 of the housing i. Due to the pivotal mounting of thesearms 15, they move from one extreme position shown at the left of Fig. 3and in which position an antenna or tape 3 is retracted or withdrawninto its casing 1, to the other extreme position shown at the rightofFig. 3 and in which position an antenna or tape 8 is in one of itsextended or withdrawn positions. When extended to any one of itsnumerous receptive positions, the folded tape is self-supported andspaced apart to such an extent as to assure most effective operation.

The lower or concaved section 8 of the tape 8 7 hold the tapetherebetween in any desired extended position in which the folded end 23of the tape is spaced at a predetermined distance from the housing I,and the folds or sections 8 and 8 of the tape 8 are in their spacedapart relation. To facilitate accurate adjustment and location of thetapes or antenna members or elements 8 until the desired or prescribedreading appears on the tape as it emerges from the slot 22 in thehousing Fig. 7 discloses another form of housing 25 for V receiving thecasings 1 containing the antenna members or tapes 8. In thisillustrative embodiment, the housing is provided with arcuate.

flanges 26 and 21 for the mounting of the casings i and with the outer,flat projections 28 of each merging with the side or end walls 29 of thehousing and disposed in spaced relation with a flange or rib 30 disposedparallel with the end 28'. As in Fig. 3, these flanges or ribs 30 andthe. flat projections 28 are spaced apart just enough to receive andpermit the tape 8 to slide freely in or out through a slot 3i in thewalls 29 of the housing, but at the same time rigidly and eifectivelyhold the tape in its adjusted position during use.

Rather than provide the pivotal arms I 5 of Fig. 3, the form shown inFig. '7 provides a pair of diagonally disposed or inclined flanges orribs 32 and 33, with the space therebetween aligned with a slot 34 inthe end walls 29 of thehousing 25. The flanges or ribs 32 and 33 arespaced apart sufficiently to receive and retain the outer end 9 of eachtape.

in Fig. 3, the ends 9 of the tapes 8 need not be flexibly connected butmay be fixedly joined together in any suitable manner.

From the above description and the disclosure in the drawing, it will beapparent that the present invention comprehends a novel indoorantennaand antenna system for the reception of radio waves, andespecially an antenna admirably adapted for the reception of televisionand frenovel antenna, ,the assembly provides a highly. compact unit thatmay be easily transported and. during inactive periods Stored in aminimum of As these flanges or ribs are fixed in position and notpivotally mounted as.

as-eszsro mately six inches long, four tofive inciieshigh andhavingianfloverallwidth' or thickness of slightly. more than one inch.Thus it will be seen thattli'einactive, assembleda'iitenna may be eas--il yll stored: or carried" about'l Although'we' have stressed the" use"of the" present antennaas b'e'ing employed-for the receptionoftelevisionand F. M. signals, it will be readily appreciated that this novelantenna is equally adapted for the transmission of signals.

Having thus disclosed the invention, we claim:

1. A folded di-pole antenna adapted to be connected to a receiver,comprising a non-conducting housing, a pair of metal casings mounted inthe housing, a coiled semi-rigid metallic tape mounted in each casing insuch manner that any desired length of tape may be selectively withdrawnor returned to its casing at will, the inner end of each tape beinganchored in its casing and its outer end withdrawn and anchored in thehousing and forming a fold outside the housing, means for electricallyconnecting the outer ends of the pair of tapes, and a conductorconnected to the casings for transmitting the energy intercepted by theeffective length of the antenna to the receiver, the folded portion ofthe tape being manually withdrawn to any predetermined length forreception of the desired signals.

2. An indoor antenna comprising a housing of non-conducting materialhaving its opposite end walls slotted, a pair of metallic casingssecured within the housing in opposed relation and a spring-loaded,semi-rigid, concave metallic tape coiled within and adapted to bewithdrawn from each casing or returned thereto, the outer end of eachtape being withdrawn from its casing through the slot in the end wall ofthe housing and with the outer end of the tape returned to and securedin the housing whereby each tape provides an adjustable loop projectingoutside the housing and forming a folded di-pole.

3. An adjustable antenna unit comprising a housing of non-conductingmaterial, a pair of metallic casings located within the housing and acoiled metallic tape carried in each casing with the inner end anchoredin the casing and the outer end projected through the housing to theexterior and then back into the housing, means for electricallyconnecting the outer ends together in the housing, and means foranchoring the outer ends in the housing whereby the portion of each tapeintermediate the outer end and that portion coiled in the casingprovides a folded dipole projecting outside the housing, said foldeddi-pole being adjustable by withdrawal of a variable length of tape fromthe casing.

4. An adjustable indoor antenna unit for a receiver comprising a housingof non-conducting material, a pair of metallic casings mounted withinthe housing in opposed relation, a coiled metallic tape provided in eachcasing with the outer end of each tape withdrawn from its casing andprojecting through the adjacent end of the housing and folded back intothe housing with the end of the tape anchored in the housing, whereby toprovide a folded di-pole at the two opposite ends of the housing, meansfor electrically connecting the ends of the tapes in the housing, and aconductor electrically connected at one end to the casings and at itsother end to the receiver.

5. In an adjustable indoor antenna for the reception of radio waves, ahousing therefor of non-conducting material, a metallic casing enclosedwithiif the housing; aunetallic spring loaded; semi=rigid concave tape"coiled within the easingwnfi" itsouterend projecting outside the? casinand means .'for anchoring the outer-ana in th'e'housingwith' the t'apebetween said outer end-and the casing being" looped outside the housingan adapted to be withdrawn from the" casing to form a folded di-poleantenna-"- thatis adjustablein length and self sup'port'ed;

(i. Iri'an'indoorantenna" for the reception of television" and frequencymodulated" signals, a housing and" support therefor" ofnon-conductiii'g' material, a sprifig loaded'metallic ta e Cbiled'iilfsaid-housing withthe outer end ofthe tapeancho'redifiiithe'fhousing'.and said tape forming an adjustable;andTseIf-supporting loop projecting outsidethehousingto provide anadjustable folded di-pole antenna, and means for connecting the ends ofthe loop to transmit the energy intercepted by the antenna to areceiver.

7. In an antenna unit for radio waves including television and frequencymodulated signals, a pair of coiled and extensible metal tapes, anonconducting housing in which said coiled metal tapes are mounted, andmeans for electrically connecting and anchoring the outer ends of thesetapes within the housing with the portion of each tape between the coilwithin the housing and the outer end thereof extending outside thehousing and thereat forming an extensible loop manually adjustable forthe desired signal.

8. In an indoor antenna unit for the reception of television andfrequency modulated signals, a pair of coiled and extensible, semi-rigidand concave metal tapes, a non-conducting housing for receiving thecoiled portion of the tapes and provided with vertically spaced slots atits opposite ends for the passage therethrough of the spaced sections ofeach of the tapes as they are withdrawn from the coils, means forconnecting together the outer ends of these coils, and means foranchoring the connected ends in the housing, the portion of these tapesbetween the anchored ends and the coiled portion in the housing forminga self-supporting and extensible loop outside and at each end of thehousing and being adjustable to form upwardly and outwardly projectingfolded di-poles.

9. An indoor antenna comprising a housing of non-conducting materialhaving its opposite end walls slotted, a pair of metallic casingssecured within the housing in opposed relation, a springloaded,semi-rigid, concave metallic tape coiled within and adapted to bewithdrawn from each casing or returned thereto, the outer end of eachtape being withdrawn from its casing through the slot in the end wall ofthe housing and with the outer end of the tape returned to and securedin the housing whereby each tape provides an adjustable loop projectingoutside the housing and forming a folded di-pole, and spaced flanges forreceiving the spaced sections of the folded tapes as they emerge fromand enter each end wall of the housing, the flanges being spaced apartjust suflicient for the reception and passage of the tapes and of suchlength as to maintain the tapes in their proper spaced and ad justedrelation.

10. An adjustable indoor antenna unit for a receiver comprising ahousing of non-conducting material, a pair of metallic casings mountedwithin the housing in opposed relation, a coiled metallic tape providedin each casing with the outer end of each tape withdrawn from its casingand projecting through the adjacent end of the housing and folded backinto the housing with the end of the tape anchored in the housingwhereby the extensible loops outside the housing provide a foldeddi-pole at the two opposite ends of the housing, means for electricallyconnecting the. ends of the tapes in the housing, spaced elongatedflanges for receiving the tapes as they emerge from the opposite ends ofthe housing, other flanges for receiving the folded and anchored ends ofthe tapes Within the housing, mean's'for pivotally mounting the lastmentioned flanges, and a conductor electrically connected atone end tothe casings and at its other end to the receiver.

' EDWARD C. HAMEL.

GLENN A. BROWN. ROBERT F. POND.

Q a: REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 2,157,278 Blackmore May 9, 19392,259,628 Bener Oct. 21, 1941 2333,52; White May 19, 1942 OTHERREFERENCES Tele-Tech, May 1948, page 85.

